A local area network system, such as the Ethernet, can be used for industrial control applications. Such a network system can be used to enable programmable controllers, host computers, control devices, such as adjustable frequency drives, and other automation devices to communicate through the production areas of an industrial plant. The devices connected together in such a communication link are generally referred to as “nodes”. Each node has a unique Media Access Control (MAC) address as an identifier of the node to allow messages from one node to be sent to another. In an automated factory where a plurality of automation devices are used to perform a variety of intended functions, each automation device has a controller, such as a programmable logic controller (PLC), to communicate with a controlling workstation or the PLC of another automation device. Furthermore, the PLC includes a software program to control the automation device in performing the intended function.
In a small, enclosed communications network such as the local area network system, any automation device can be easily tracked down by a monitoring mechanism within the network using the MAC address of the device. However, it is not as easy to keep track of a factory automation device from the outside of that local area network system. It is even more difficult to monitor a factory automation product that does not have a MAC address or other address accessible via a communications network. For example, it is rather difficult for the manufacturer of a software program or other similar factory automation product to identify the user of the product in order to determine whether the product is used in violation of licenses, or to notify the user of product safety or quality issues. Furthermore, it is also desirable for the manufacturer to determine whether the product is being illegally duplicated, or whether the product is used in compliance with an export license.
Thus, it is advantageous and desirable to provide a method and system for monitoring the users of factory automation products through a communications network such as the Internet.